Manifold battery for hydrocarbon fields

ABSTRACT

A manifold battery for hydrocarbon fields has an entrance manifold which is connected to a plurality of separators which are operatively connected through ducts and valve sets, with gas storage devices and a pair of circulating pumps. A purging chamber is also provided which is connected to the storage devices and to the separators. An auxiliary tank reduces the adverse impact to the environment, accidents, dangers and consequential risks of flammable, toxic and damaging substances concentration, as well as reducing the operative times and the related costs.

This application is based on and claims the benefit of priority fromprior Argentine Patent Application No. 2013 010713, filed Mar. 5, 2013,the entire contents of which are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention is related to the field of means or dispositionsemployed for the temporary storage and treatment of hydrocarbons, moreparticularly, it refers to a manifold battery that, unlike traditionalbatteries, reduces the impact on the environment, the consequentialaccidents, dangers and risks of the flammable, toxic and damagingsubstances concentration, as well as the operative times and connectedcosts.

Even when the present description refers more particularly to thetechnical and commercial advantages of its implementation as a manifoldbattery for hydrocarbon fields, it is clear that its use accommodatesthe pertinent environmental safety rules and cooperates with awarenessfor the environment.

BACKGROUND

In order to better understand the purpose and scope of the presentinvention, it is convenient to describe the current state of the artregarding the traditional manifold tanks or batteries used and thedrawbacks that occur.

Manifold batteries are well known in the field of the art and it is wellknown that they receive the oil extracted from the wells, to treat thesame in a first stage prior to its refining process. A battery isgenerally used in small plants constituted by a collector or “manifold”,such as it is known in the art, provided in the battery entrance to beconnected to the plurality of wells available in the place, and toreceive the oil which is simultaneously extracted from them. In turn, itis known that the oil comes accompanied by gas and water, among othercomponents, for which a gas separator, a pair of heaters, a plurality ofgeneral production tanks (160 m3) and control tanks (40 m3), some pumps,flowmeters, liquid separators, etc. are provided. Thus, the oil, thewater and the natural gas coming from the wells flow are separated inthe mentioned tanks and separated by diverse methods, subsequently beingprepared for the following treatments or purposes.

In addition, the storage tanks are designed to store and handle greatoil and gas volumes, being generally of big dimensions. The storageconstitutes a valuable element in the exploitation of hydrocarbonservices since it acts as a core zone between production and/ortransportation to absorb the consumption variations. Known tankscomprise a cylindrical form with a flat bottom, vaulted top structure,being floating some times, so as to avoid flammable gas accumulationwithin them. The tanks may be or not be provided with a heating system.

On the other hand, in case an extremely dangerous defect or drawback inthe mentioned tanks occurs, there will be a containment pool surroundingeach of them, in order for a rapid evacuation so as not to damage andimpact the environment.

However, the batteries' infrastructure demands high economicinvestments. This occurs since the conditions in which both the oil andthe gas have to be stored in such storage tanks are quite specific and,consequently, the materials used for their construction present veryhigh costs. In turn, due to safety matters, such pools surrounding eachof the tanks are built, leading to an additional cost. To this, thecosts for the periodic controls carried out are added, as well as thefacilities maintenance, more particularly the storage tanks, whichgenerate high costs for the use of heavy machinery and time loss, whichcould be used to optimize production. So, the purchase, assembly,installation and maintenance of the storage tanks generate high costswhich very few companies may bear.

On the other hand, tanks which comprise big dimensions, store a greatamount of oil and gas that may be dangerous in the event that they arenot in optimal conditions, and due to various reasons, leaks or othertypes of drawbacks that occur endangering operators, the production zoneand especially the environment.

Considering the current state of the art available for manifoldbatteries, it would be advantageous to have a new manifold battery,constituted and constructed to reduce the impact on the environment, theaccidents, dangers and consequential risks of the flammable, toxic anddamaging substances concentration, as well as the operative times andthe connected costs.

Therefore, it is one of the purposes of the present invention to providea new manifold battery which is constituted and constructed to reducethe impact on the environment, the accidents, dangers and consequentialrisks of the flammable, toxic and damaging substances concentration, aswell as the operative times and the connected costs.

Another purpose of the present invention is to provide a manifoldbattery which reduces the costs, as well as, the generation,accumulation and release of gases, thus achieving a greater operativesecurity.

Another purpose of the present invention is to provide a manifoldbattery which adjusts to the needs of individual circumstances, beingable to adapt as a mobile battery to measure the wells, either inmarginal, new or distant fields.

Still another purpose of the present invention is to provide a manifoldbattery that reduces the environmental impact.

SUMMARY

In keeping with one aspect of the present invention, a manifold batteryfor hydrocarbon fields includes an entrance manifold which connects to aplurality of separators, which are operatively interconnected throughducts and valve sets, with a disposition of gas storage devices and aset of circulating pumps. A purging chamber connects to the storagedevices and separators. The manifold battery has three-way valvesconnected to at least a general line and at least a control line. Theseparators are connected to the general and control lines, and includeat least two control separators and at least two general separators areconnected among themselves, providing an auxiliary tank connected tothose separators and to those circulating pumps through the respectiveducts and valve sets, wherein one of the gas storage devices is areserve gas vessel for instruments.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding and clarity of the present invention purpose,the same has been illustrated in a unique drawing, in which theinvention has been represented in one of the preferred performanceforms, all at the example title, where:

FIG. 1 shows a schematic diagram of the present manifold battery.

DETAILED DESCRIPTION

Referring to FIG. 1, a new manifold battery for hydrocarbon fields isconstituted and constructed to significantly reduce adverse impact onthe environment, avoid gas accumulation which may endanger the facilityand operators, and particularly reduce the operative costs and times.

The manifold battery for hydrocarbon fields of the present inventionincludes an entrance collector or “manifold” 1 constituted by athree-way valve disposition which present at least a general line 1A andat least two control lines 1B and 1C, being interconnected to aplurality of separators by means of an entrance valve set 2A, 2A′ and2A″ respectively. All the production of a determined field derives tosuch three-way valve disposition, where the complete production flowsthrough the general line 1A, while the control lines 1B and 1C are usedto evaluate the individual production of a determined well.

The plurality of separators includes at least two general separators 3Aand at least two control separators 3B. That is why the hydrocarbonscoming from the manifold 1 through the general line 1A pass through theentrance valves 2A and enter the general separators 3A, while thehydrocarbons flowing through the control lines 1B and 1C, pass throughthe valves 2A′ and 2A″ respectively, and enter the control separators3B. In the general 3A and control 3B separators, hydrocarbons areseparated by decantation, remaining in the liquid phase in the bottomzone of them, while the gaseous phase is in the upper one. Once thegeneral 3A and control 3B separators have accumulated a pre-establishedlevel, the opening of one of the control 2B valves occurs for the caseof separators 3A, and of one of the control valves 2B′ and 2B″ for thecase of 3B separators, respectively, so as to send the fluid to adischarge line 4, towards a circulating pump set 5. In addition, the gasis evacuated from a set of exit valves 2C in the case of generalseparators 3A, while it is evacuated from control separators 3B by a setof exit valves 2C′ and 2C″, towards a gas storage disposition device.

Referring again to the circulation pumps 5, the same comprise a firstoperation pump 5A and a second auxiliary pump 5B, where both circulatingpumps are the type comprising a double effect piston, with a flow of atleast 185 m3/h minimum at a maximum labor pressure of 75 kg/cm2, and aminimum suction pressure of at least 1 Kg/cm2. The circulating pump 5Aoperates in a constant manner, evacuating the production, while, suchcirculation pump 5B begins operating when pump 5A is under preventivemaintenance and/or under eventual fault.

In regards to the gas storage devices, they include a gas separator 6which allows the elimination of the liquid existing in the gas comingfrom the separators 3A and 3B, a burning ditch 6A and a reserve gasvessel for instruments 6B which feeds the facility instruments with gas.That is how gas evacuates from the separators 3A and 3B, passesprimarily through a gas measuring bridge, and then resides in the gasseparator 6 and/or in the burning ditch 6A and/or in the reserve gasvessel 6B.

The excess gas is evacuated and directed to related motor compressorstations or treatment plants by means of a valve 6C. In addition, thementioned gas measuring bridge has a first pneumatic valve 6D and asecond pneumatic relief or venting valve 6E. The first valve 6D isconnected to the general gas separator 6, while said second valve 6E isconnected to the burning ditch 6A. The latter is activated in case thepressure is higher than that established in the event of the gaspipeline break.

It should be pointed out that the liquid that is separated from the gaswithin the gas separator 6, is purged and discharged through a valve 6Ftowards a purging chamber 7, which receives all of the purges of all theprocess elements through the purging lines 4A and which have anemergency pool and a level indicator. Generally, the gas captured in thebatteries is for consumption, as heater fuel, explosion motors,instrument gas, while the excess gas is destined for sale.

The manifold battery is provided with an auxiliary tank 8 connected tothe separators 3A and 3B, and to the circulation pumps 5A and 5B,through the respective ducts and valve sets, where it has at least oneentrance valve 8A, a pneumatic control valve 8B, at least an overflowpipe 11 and a pneumatic controller configured with a pressure lower thanthe separators' working pressure. It is then that, in the case of faultin the facility, either by the separators or by the pumps, thehydrocarbon production enters the tank 8, through the entrance valve 8Awhich is activated by the pneumatic controller. When such productionreaches a determined level within the tank 8, it sends a signal to aremote terminal unit “RTU”, which controls the opening of the pneumaticvalve 8B and the closing of a pneumatic valve located between the pumps5A and 5B. The remote terminal unit RTU is of the type that performs thecollection of the information supplied by the sensors connected to theprocess, the command of final control elements and the communicationwith a control center. Thus, pump 5B starts operating so that itevacuates the tank production 8. On reaching a vacuum pre-establishedheight level, it should close the pneumatic valve 8B and stop pump 5B.In the event that the tank 8 overflows, there is an overflowing pipe 11provided with a pneumatic valve and a level sensor which opens andevacuates the production to the purging chamber 7 through the purgingline 4A, avoiding in this way leaks in the facility zones and theconsequential environmental impact.

On the other hand, each general separator 3A has a level sensor 12 whichacts when the interface level exceeds the point established activatingthe entrance pneumatic valve 2A, closing and diverting the production tothe other general separator 3A. Moreover, it has a pressure sensor 13which acts when the working pressure declines, activating the entrancepneumatic valve 2A so that it closes and directs the production to theother general separator 3A. In the event of fault in both generalseparators 3A, either by level or by pressure, production is diverted tothe tank 8 through a relief valve 10 that acts by pressure. In fact,each control separator 3B also has a level sensor 14 which acts when theinterface level exceeds the established point, activating a three waypneumatic valve which delivers the production through the individualline and through the general separators 3A entrance. It also has apressure sensor 15 which, when the separator working pressure 3B isunder the established point, activates the three way pneumatic valveclosing the same, passing the production by individual line and bygeneral separators entrance line. It may be pointed out that each of theseparators 3A and 3B are provided with a level controller 16, a sensorand pressure transmitter 17 and principally with a continuous levelcontroller 18, which prevents the pumps 5A or 5B from working in faultor being stopped due to fault of a minimum flow. In the event that allof the general separators 3B and control separators 3B start working infault, control separators 3B production is diverted through valves 2A′and 2A″ to the entrance line of the general separators 3A andafterwards, starting from them, diverting to tank 8 through relief valve10.

It is thus that the hydrocarbons coming from the wells are primarilydelivered to the battery through collector 1 which allows deliveringthem to different separators, having two control separators 3B and twogeneral separators 3A, where the control separators 3B allow determiningthe individual production of each well by mass sensor meters. In thegeneral separators 3A, the general production is passed and the liquidphase is separated from the gaseous phase by densities difference, wherethe gaseous phase is directed to the gas pipeline or gas separator 6 andthe liquid phase is discharged to a suction pipe or discharge line 4which otherwise goes directly to pumps 5A or 5B, which send thepreviously separated oil to the crude treatment plant.

Thus, the manifold battery of the present invention reduces the impactto the environment, preventing gas accumulation which may endanger thefacility or the operators, due to the fact that it prevents the use ofthe usual storage tanks in the traditional batteries, reduces thepurchase, assembly and maintenance costs, and notoriously optimizes theoperative times.

1. A manifold battery for hydrocarbon fields comprising: an entrancemanifold connected to a plurality of separators, which are operativelyinterconnected through valve ducts and valve sets, a gas storage deviceand a set of circulating pumps, and a purging chamber connected to saidstorage device and said separators, and an auxiliary tank connected tosaid separators and to said circulating pumps through the respectiveducts and valves sets, and wherein said manifold comprises a three-wayvalve disposition which present at least a general line and at least acontrol line, said plurality of separators is connected to said generaland control lines, and comprises at least two control separators and atleast two general separators connected among themselves, wherein atleast one of said gas storage devices is a reserve gas vessel forinstruments.
 2. The battery of claim 1, wherein since each of saidcontrol and general separators are connected to entrance valves and tocontrol valves.
 3. The battery of claim 2, wherein said control andgeneral separators are provided with outlet valves and a relief valve.4. The battery of claim 1, wherein said control separators have a levelsensor, a pressure sensor and a mass sensor, while said generalseparators have at least a level sensor and a pressure sensor.
 5. Thebattery of claim 4, wherein said control separators and generalseparators have a level controller, a sensor, a pressure transmitter,and a continuous level controller.
 6. The battery of claim 1, whereinsaid auxiliary tank is provided with at least an entrance valve, apneumatic control valve, at least an overflow pipe and a pneumaticcontroller configured with a pressure lower than the separators workingpressure.
 7. The battery of claim 1, wherein said gas storage devicesalso comprise a gas general separator which is connected to said purgingchamber and to said gas vessel by means of a gas measuring bridge. 8.The battery of claim 7, wherein said gas measuring bridge comprises afirst pneumatic valve and a second relief or venting pneumatic valve,said first valve being connected to said gas general separator, whilesaid second valve is connected to a burning ditch.
 9. The batteryaccording of claim 1, wherein said circulating pumps comprise a firstoperating pump and a second auxiliary pump.
 10. The battery according ofclaim 9, wherein said circulating pumps comprise a double effect piston,with a flow of at least 185 m3/h at a minimum maximum working pressureof 75 kg/cm2, and a minimum suction pressure of at least 1 Kg/cm2.